It has been mentioned earlier that the Mahabharata was in the custody of the Brahmins of the Bhrgu race. The epic got its vast size even before the rise and development of the Gupta reign. The tendency to enlarge the Mahabharata text was still continued by these Brahmins. In their own interest, these Brahmins wrote the Puranas and rearranged them. It is a notable fact that Lord Krishna had not a prominent role to play even in the first connected epic narrative. The studies of Sri V.S. Sukthankar reveal the fact that the very first stanza 'नारायणं नमस्कृत्य" etc. is a later interpolation to the Mahabharata, a pure Vaishnava composition.
The above passage was quoted from sodhganga articles already by an user here.
My question is what are those studies and what are the evidence available to support these claims.